Turbo Lude Not Likin Vtec

well guys i am new to this board and i am havin a hell of a time tryin to figure out what the hell the prob is.

I have a 94 si with a 99 vtec engine. i have turboed the engine with a kit that i built (NOT a hack job Junkyard Wars kit). it consist of a vortech fmu 10.1, walbro 255lph in tank pump, front mount intercooler, equal lenght manifold, t4 turbo, turbo xs bov, dsm turbo 440cc injectors, tial 35mm wastegate, Apexi VAFC and autometer gauges.

The issue i am having is vtec. IT HATES IT. under full throttle 10lbs of boost and it caughs out the exhaust. could i have to much overlap in vtec? i was cosidering a exh cam gear? The cams are stock and as far as what else i have been told they are saying its fuel.

I had the close to same setup less the vafc on a h23 and had no prob lem at all rippin the tires loose at 40 mph

Well, I'd probably defer to the turbo guys on the board, but I think you're right on thinking that you're getting too much overlap in VTEC. That would also explain why a similar setup with an H23 caused you no problems. Before some dyno tuning, I think you need to get yourself a set of adjustable cam gears, and maybe some turbo-ready cams to tune your setup.

The adjustable cam gears have nothing to do with how long the valves stay open or closed. Just WHEN. Your problem is that you have too much overlap when VTEC engages. So you'll want to advance the exhaust cam to get less overlap.

try ditching the fmu and running the big injectors and -40 idle and -35% fuel cut for the rest...adjust it to perfection on the dyno

geez thats scarry BUT if i was to use a fmu what reation would you recomend? and also do you have a graph pic of the setting you talk about on the vafc?
I am just kinda wondering about the vafc and no fmu because the boost will always come in at a differein spot depending on the load on the engine, right? Well if you are runnin down the road at 3k in fifth and come up on a hill and the turbo begins to build boost, would you or not still have the same fuel mapping adn the engeni would go lean? just a thought.

i have a pair of TODA cam gears....150 OBO

Click to expand...

Are the cam gears are for an h22? whats the lowest you will go if i overnight you a moneyorder?